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Joint Compound or Tape

06-26-2010, 11:17 PM

Okay so I have a general question but more specifically regarding gas pipe joints - is one better than the other. So far I've always used tape and with appropriate tightening my TIF gas detector usually cannot pickup any leaks. But I noticed that it seems like near my gas meter they seem to have used joint compound. Just made me think if there are specific situation where one is better than the other like outdoor vs indoor.

Comment

rectumseal #5 for gas. it's what the gas boys use and it works great. everything else is laco slic-tite or millrose three wrap red waterline (pink) tape. nobody sell blue monster here, so i don't know about it. breid..............

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personally i use dope but teflon can be used if you're careful about how you apply it. teflon being very light in weight can actually float through the system and get into the gas valve or pilot assembly.

you need to wrap the tape in the direction of tightening so the tape doesn't unwrap. but the most important is that you don't apply any tape beyond the end of the pipe. this is where the potential for the tape to tear off and move down the line.

other problem with teflon is that it doesn't do too well if you tighten and then back off the thread 1/2 a turn.

modern dope is available with teflon particles in it giving you the best of both worlds.

at 1 time i was able to buy ridigid white dope with teflon at home depot i like the creamy consistency of it and the way it flowed.

can't find it anymore and i need to find a new dope dealer

p.s. you'll have much better success with soap and a spray bottle to check for leaks as the tif sniffer will pick up on any combustibles such as the oils in the dope of course a 10# air test is required on work unless it was a minor repair such as a valve swap or nipple and 90. plus the soap will help you clean up after yourself so you don't end up with dirtyhands

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Thanks for the replies. Good points by Rick. Yes, I've always been careful to not have any tape off the end of the pipe and also wrap it so that it does not unwrap while tightening. Also if I had to back off a joint I always redid the tape.

Based on the responses I guess I will switch to joint compound. The dope I currently have (I think Otaey or some such brand) does say with Teflon.

Regarding the TIF detector - maybe it's me but I've had it pickup trace leaks when the leak detection spray has not been able to. It's possible I was not doing it exactly correctly with the fluid. The TIF specs say detection down to 50ppm - I find it hard to believe you can see a 50ppm leak with soap and water but then again I'm not a plumber so what do I know .

Easy way to calibrate the TIF is to have it sniff the dope first - if it does not sense anything then it should be okay to use for detection.

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what kind of leak detection solution are you using before you use the sniffer??? In some cases, if the pipe has been sprayed with certain soaps it will give a false positive on the sniffer.

It's the one that came in a spray bottle from HD. I'm not sure if could have been due to the soap since tightening it somewhat further caused the sniffer to stop beeping. It suppose it is always possible - I think I still have some left over - if I have a moment I will test the sniffer with the dope and the leak detection fluid and see if that's the reason.

I do use it with pipe dope Recto seal T+2 on pipes 1.25 and better. Otherwise I just use the paste.

As for the TIF it is a great tool to narrow the search before soaping. The right soap is also important. Tru-Blue is the best I have available now. It has a very high viscosity and shows snowball leaks. It is also non-corrosive to the pipe.

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That's interesting - did not realize it was not legal in places although it seems that way with seeing some of the earlier posts. It is legal here as far as I know (or at least used to be) - I checked with the plumbing inspectors on my last gas line project beforehand and it passed inspection.

I just picked up a can of the Rectorseal (something like T+2 if I recall) this evening along with the coated pipes for the outdoor part of the project.